about summary refs log tree commit homepage
path: root/lib/mongrel/http_response.rb
blob: 30767127ff368ca6beb0270e4bb462df49c23d3b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
module Mongrel
  # Writes and controls your response to the client using the HTTP/1.1 specification.
  # You use it by simply doing:
  #
  #  response.start(200) do |head,out|
  #    head['Content-Type'] = 'text/plain'
  #    out.write("hello\n")
  #  end
  #
  # The parameter to start is the response code--which Mongrel will translate for you
  # based on HTTP_STATUS_CODES.  The head parameter is how you write custom headers.
  # The out parameter is where you write your body.  The default status code for 
  # HttpResponse.start is 200 so the above example is redundant.
  # 
  # As you can see, it's just like using a Hash and as you do this it writes the proper
  # header to the output on the fly.  You can even intermix specifying headers and 
  # writing content.  The HttpResponse class with write the things in the proper order
  # once the HttpResponse.block is ended.
  #
  # You may also work the HttpResponse object directly using the various attributes available
  # for the raw socket, body, header, and status codes.  If you do this you're on your own.
  # A design decision was made to force the client to not pipeline requests.  HTTP/1.1 
  # pipelining really kills the performance due to how it has to be handled and how 
  # unclear the standard is.  To fix this the HttpResponse gives a "Connection: close"
  # header which forces the client to close right away.  The bonus for this is that it
  # gives a pretty nice speed boost to most clients since they can close their connection
  # immediately.
  #
  # One additional caveat is that you don't have to specify the Content-length header
  # as the HttpResponse will write this for you based on the out length.
  class HttpResponse
    attr_reader :socket
    attr_reader :body
    attr_writer :body
    attr_reader :header
    attr_reader :status
    attr_writer :status
    attr_reader :body_sent
    attr_reader :header_sent
    attr_reader :status_sent

    def initialize(socket)
      @socket = socket
      @body = StringIO.new
      @status = 404
      @reason = nil
      @header = HeaderOut.new(StringIO.new)
      @header[Const::DATE] = Time.now.httpdate
      @body_sent = false
      @header_sent = false
      @status_sent = false
    end

    # Receives a block passing it the header and body for you to work with.
    # When the block is finished it writes everything you've done to 
    # the socket in the proper order.  This lets you intermix header and
    # body content as needed.  Handlers are able to modify pretty much
    # any part of the request in the chain, and can stop further processing
    # by simple passing "finalize=true" to the start method.  By default
    # all handlers run and then mongrel finalizes the request when they're
    # all done.
    def start(status=200, finalize=false, reason=nil)
      @status = status.to_i
      @reason = reason
      yield @header, @body
      finished if finalize
    end

    # Primarily used in exception handling to reset the response output in order to write
    # an alternative response.  It will abort with an exception if you have already
    # sent the header or the body.  This is pretty catastrophic actually.
    def reset
      if @body_sent
        raise "You have already sent the request body."
      elsif @header_sent
        raise "You have already sent the request headers."
      else
        # XXX Dubious ( http://mongrel.rubyforge.org/ticket/19 )
        @header.out.close
        @header = HeaderOut.new(StringIO.new) 
        
        @body.close
        @body = StringIO.new
      end
    end

    def send_status(content_length=@body.length)
      if not @status_sent
        @header['Content-Length'] = content_length if content_length and @status != 304
        write(Const::STATUS_FORMAT % [@status, @reason || HTTP_STATUS_CODES[@status]])
        @status_sent = true
      end
    end

    def send_header
      if not @header_sent
        @header.out.rewind
        write(@header.out.read + Const::LINE_END)
        @header_sent = true
      end
    end

    def send_body
      if not @body_sent
        @body.rewind
        write(@body.read)
        @body_sent = true
      end
    end 

    # Appends the contents of +path+ to the response stream.  The file is opened for binary
    # reading and written in chunks to the socket.
    #
    # Sendfile API support has been removed in 0.3.13.4 due to stability problems.
    def send_file(path, small_file = false)
      if small_file
        File.open(path, "rb") {|f| @socket << f.read }
      else
        File.open(path, "rb") do |f|
          while chunk = f.read(Const::CHUNK_SIZE) and chunk.length > 0
            begin
              write(chunk)
            rescue Object => exc
              break
            end
          end
        end
      end
      @body_sent = true
    end

    def socket_error(details)
      # ignore these since it means the client closed off early
      @socket.close rescue nil
      done = true
      raise details
    end

    def write(data)
      @socket.write(data)
    rescue => details
      socket_error(details)
    end

    # This takes whatever has been done to header and body and then writes it in the
    # proper format to make an HTTP/1.1 response.
    def finished
      send_status
      send_header
      send_body
    end

    # Used during error conditions to mark the response as "done" so there isn't any more processing
    # sent to the client.
    def done=(val)
      @status_sent = true
      @header_sent = true
      @body_sent = true
    end

    def done
      (@status_sent and @header_sent and @body_sent)
    end

  end
end